I hope so. The fact that the sub-only volumes have nine episodes means it could be argued that the bilingual ones should too, although that seems a bit unfair to the people who bought the sub-only ones. Overall, it is unlikely that the first dub DVRAB of any 26 (27 in this case) episode anime series will each have a third of the series. However, this is not a typical case, not only for the reason you stated, but because the sub-only volumes will all be out by then, the dub has probably already finished recording, and the dub will have finished on TV by then. So we'll just have to wait for the news, but either way, that box is just too awesome not to get no matter how many episodes it has.